HI, I HAVE A LOUD STRANGE NOISE FROM MY CAR. ITS A 2002 E53 4.4I. ITS SOUNDING LIKE A HOOVERCRAFT. WE HAD THE CAR TAKEN APART TO CHANGE THE TIMING CHAIN GUIDES AND WHEN WE PUT IT TOGETHER WE HAVE THIS NIOSE COUPLED WITH A AMBER LIGHT ON DASH (deterioration of exhaust emission control values?)
the only thing i can think of is that we started the car with a pipe off the secondary air pump but fixed this.
does anyone have any ideas? this car is costing me a fortune!!
video of problem
bmw x5 engine noise! sounds like hoovercraft, please help! - YouTube
it varies with revs and never goes away!